Diffusion and Osmosis

Uses Energy
Low to high concentration

Example: Endocytosis, Exocytosis

​Active Transport

Does not use energy
High to low concentration

Example: Diffusion, Osmosis, Facilitated diffusion

​Passive Transport

Facilitated Diffusion

Some molecules are too big to cross the membrane on its own, so a protein channel in the membrane will allow it to pass. Proteins in the membrane create a channel.
- Facilitate means "make easier"
so facilitated diffusion = makes diffusion easier

​Diffusion, Osmosis, Facilitated Diffusion

The cell membrane is selectively permeable. It allows certain things to come in or out of the cell such as water. sugar, oxygen, carbon dioxide.
It does this by either passive transport or active transport.

Passive transport: movement of molecule without the use of energy
- Diffusion: movement of molecules from an area of high concentration to low concentration.
- Osmosis: Movement of water molecules across a membrane.
- Facilitated Diffusion: When molecules are too big they use a channel to move across the membrane.

Active transport: Uses energy, Low to High concentration